Couldn't disagree more on his statement: "Never start a company just to start it. You start a company because you have an idea that you think will be great for some customer and great ideas are always worth doing"

IMHO the biggest reasons to start a company is just to start it. The biggest companies have started that way - most famously HP. Ideas are mostly incidental and most of the time the first ones rarely work out. The biggest ideas are not really that clear early on - Writely was only a great idea because it got acquired by Google.